CN114103019B - Adjustable pitched roof back-off mechanism and back-off method for injection mold - Google Patents

Abstract

The invention discloses an adjustable inclined ejection back-off mechanism and a back-off method of an injection mold, wherein the back-off mechanism comprises a mold core and a mold cavity, and also comprises an adjustable back-off component, the adjustable back-off component is arranged on the mold core in a sliding manner, an injection cavity with a plurality of back-off structures is formed between the adjustable back-off component and the mold cavity, the back-off directions of the back-off structures are different, and the adjustable back-off component moves towards one back-off direction while moving along the mold opening direction. The invention avoids the exposure of the clamping wires and ensures the consistency of the appearance; not only realizes that the product is driven by the locking during the first section die opening, but also realizes the back-off during the second section die opening; the two-section die opening mode is adopted, the first section die opening realizes the back-off of the cavity, the second section die opening can realize the complete opening of the cavity and the back-off of the sliding block at the same time, and the efficiency is improved; the die has simple structure and is simple and convenient to use and operate.

Description

An injection mold adjustable inclined ejector undercut mechanism and undercut method

Technical Field

The invention relates to the technical field of molds, and in particular to an injection mold adjustable inclined top undercutting mechanism and an undercutting method.

Background technique

A large number of plastic parts usually encounter the situation of undercut during injection molding and demolding. Undercut is a structural part of the product that "reversely covers" the mold, which makes the product unable to be demolded smoothly in one direction. Some plastic parts are equipped with many flanges and undercuts due to assembly needs. The undercut structures are respectively arranged on the front and side of the product. Therefore, the corresponding mold is usually provided with multiple undercut structures corresponding to different undercut directions. The commonly used mold structure is external parting, which usually has a large straight top and a large inclined top, and a slider is also provided to make the product detach from the undercut. The disadvantage of this type of structure is that the clamp line is exposed, which affects the appearance. A large number of injection molded parts in automotive parts are manufactured using this method. However, automotive parts have high requirements for appearance. The exposed clamp line makes the external parting design unsuitable for injection molding of automotive parts.

For example, a "clip line easy-to-match combined external parting insert automobile bumper lower mold structure" disclosed in Chinese patent documents, with application number CN201921473972.7, includes a lower module, the top of which is provided with a lower mold core for forming an automobile bumper, the lower module is provided with a number of high-precision clip line insert assemblies symmetrical along the center line of the lower module, the high-precision clip line insert assembly is tightly matched with the lower mold core, the lower mold core is provided with a number of external parting inserts symmetrical along the center line of the lower mold core, and the width of the high-precision clip line insert assembly is greater than the width of the lower mold core. The disadvantage is that this solution is easy to produce clip lines on the outer surface of the bumper, affecting the appearance.

Summary of the invention

The present invention aims to overcome the problem that the mold stripping undercut structure in the prior art is prone to produce clamping lines on the outer surface of the product, and provides an injection mold with an adjustable inclined top stripping undercut mechanism and a stripping method, so as to avoid the production of clamping lines on the outer surface of the product, ensure the appearance, and have high demoulding efficiency.

In order to achieve the above object, the present invention adopts the following technical solutions:

An adjustable tilted ejector and undercut mechanism for an injection mold comprises a core and a cavity, and also comprises an adjustable undercut assembly, wherein the adjustable undercut assembly is slidably arranged on the core, and an injection cavity with a plurality of undercut structures is formed between the adjustable undercut assembly and the cavity, wherein the undercut structures have different undercut directions, and the adjustable undercut assembly can move in one of the undercut directions while moving along the mold opening direction.

The feature of the present invention is that an adjustable undercut assembly is provided to drive the product to deform and realize undercut. When the mold is opened in the first stage, the adjustable undercut assembly and the cavity are lifted up together. Since the adjustable undercut assembly is tilted on the core, it moves away from the cavity while sliding upward, driving one end of the product to move away from the cavity and deform, thereby realizing the undercut structure on the end face of the product facing the cavity. Since the product is provided with a plurality of undercut structures that are dependent on the undercut direction, while realizing the undercut of the above undercut structure, there are still undercut structures that have not realized the undercut, so the adjustable undercut assembly can drive the product to move and deform; at the same time, since the adjustable undercut assembly realizes the undercut in the direction of the cavity, there is no need to set an external parting on the cavity, avoiding the exposure of the clamp line and ensuring the consistency of appearance.

Preferably, the undercut structure includes a first undercut structure and a second undercut structure with different undercut directions, and the adjustable undercut assembly includes a large inclined top and a slider, the large inclined top is slidably arranged on the core, and the large inclined top moves along the mold opening direction and simultaneously moves toward the undercut direction of the first undercut structure, and the slider is slidably arranged on the large inclined top along the undercut direction of the second undercut structure.

The slider is set to correspond to the second undercut structure. During the first stage of mold opening, the slider moves synchronously with the large inclined top. Due to the matching relationship between the slider and the second undercut structure and the different undercut disengagement directions of the two undercut structures, the product can be deformed while moving. After completing the first stage of mold opening, the slider moves on the large inclined top to exit the undercut stroke, realize the undercut disengagement of the second undercut structure, and the product is demolded. By setting the slider, both the locking and driving of the product during the first stage of mold opening and the undercut disengagement during the second stage of mold opening are realized. Since the undercut disengagement of the cavity has been realized in the first stage of mold opening, the full opening of the cavity and the undercut disengagement of the slider can be realized at the same time in the second stage of mold opening, thereby improving efficiency.

Preferably, an oil cylinder is provided on the large inclined roof, and an output end of the oil cylinder is fixedly connected to a sliding block.

The oil cylinder drives the slide to move, which can achieve larger loads.

Preferably, the large inclined roof is provided with a pressure strip extending along the moving direction of the slider, and the slider is slidably arranged between the pressure strip and the large inclined roof.

The pressure strip serves to guide the slider.

Preferably, it further comprises an inclined ejector rod and a universal slide, wherein the bottom end of the inclined ejector rod is movably connected to the universal slide, and the top end of the inclined ejector rod is connected to the bottom of the adjustable undercut assembly.

The universal sliding seat is pushed upward, driving the inclined ejector rod to push up the adjustable undercut assembly obliquely upward.

Preferably, a plurality of sliders and oil cylinders are provided, and each slider is slidably arranged corresponding to the remaining stripping directions.

Different sliders correspond to the other undercut structures, and several sliders can be used to remove the undercuts at the same time.

A method for removing undercuts from an injection mold comprises the following steps:

a. The adjustable undercut assembly and the cavity rise synchronously to perform the first stage of mold opening. The adjustable undercut assembly moves away from the cavity while rising. The adjustable undercut assembly pulls one end of the product out of the cavity through cooperation with the undercut structure to complete the first stage of undercut removal;

b. Complete the removal of the undercuts of the remaining undercut structures and open the cavity for the second stage of mold opening.

Preferably, in step b, the slide block is driven by an oil cylinder to move on the large inclined top along the direction of disengaging the undercut of the remaining undercut structures.

Therefore, the present invention has the following beneficial effects: (1) by setting an adjustable undercut assembly, undercut can be achieved in the direction of the cavity, and no external parting is required on the cavity, thereby avoiding the exposure of the clamping line and ensuring the consistency of appearance; (2) by setting a slider, both the locking and driving of the product during the first stage of mold opening and the undercut during the second stage of mold opening are achieved; (3) in the two-stage mold opening form, the first stage of mold opening achieves the undercut of the cavity, and the second stage of mold opening can simultaneously achieve the full opening of the cavity and the undercut of the slider, thereby improving efficiency; (4) the mold structure is simple and easy to use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of an adjustable buckle assembly of the present invention.

FIG. 2 is a schematic diagram of the structure of the present invention in a mold closing state.

FIG3 is a schematic diagram of the structure of the first stage of the present invention in the mold opening state.

FIG. 4 is a schematic diagram of the structure of the second stage of the present invention in the mold opening state.

FIG. 5 is a schematic structural diagram of a product of the present invention in a demoulding state.

In the figure: 1, large inclined ejector, 11, pressure strip, 2, slider, 21, second slider, 3, cylinder, 31, second cylinder, 4, inclined ejector rod, 41, universal slide, 42, ejector plate, 5, core, 51, lower composite plate, 6, cavity, 61, upper composite plate, 7, bumper, 71, first undercut structure, 72, second undercut structure.

Detailed ways

The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in FIG. 1 and FIG. 2, an injection mold can adjust the inclined top to release the buckle mechanism, which is used for the bumper 7 to release the buckle. The front end of the bumper 7 is provided with a plurality of first buckle structures 71, and the side of the end of the bumper 7 is provided with a second buckle structure 72. The buckle release mechanism includes:

The upper composite plate 61 and the lower composite plate 51 are connected to the cavity 6 below the upper composite plate 61, and the core 5 is connected to the lower composite plate 51. It also includes an adjustable stripping undercut assembly, which is slidably arranged on the core 5, and an injection cavity is formed between the adjustable stripping undercut assembly and the cavity 6. The adjustable stripping undercut assembly includes a large inclined top 1 and a slider 2. The large inclined top 1 is a plate-shaped structure as a whole, and is obliquely slidably arranged on the core 5. The large inclined top 1 moves in the mold opening direction and moves in the stripping direction of the first undercut structure 71. The slider 2 is slidably arranged on the side of the large inclined top 1 facing the cavity 6 along the stripping direction of the second undercut structure 72. One side of the slider 2 is arranged corresponding to the second undercut structure 72. The large inclined top 1 is provided with an oil cylinder 3, and the output end of the oil cylinder 3 is fixedly connected to the other side of the slider 2. The other side of the large inclined top 1 is slidably provided with a second slider 21, and the second slider 21 is arranged corresponding to the other side of the bumper 7 and is driven by the second oil cylinder 31. The large inclined roof 1 is provided with a pressure strip 11 extending along the moving direction of the slider 2 and the second slider 21 , and the slider 2 and the second slider are respectively slidably arranged between the upper and lower pressure strips 11 and the large inclined roof 1 .

An ejector plate 42 is arranged in the space between the core 5 and the lower composite plate 51, and a universal slide 41 is arranged on the ejector plate 42. An inclined ejector rod 4 is movably arranged in the universal slide 41. The inclined ejector rod 4 extends upward through the top of the core 5 and is fixedly connected to the bottom of the large inclined ejector 1.

A method for removing an undercut comprises the following steps:

As shown in Figure 2, in the mold closing state, an injection cavity for the bumper 7 is formed between the large inclined top 1, the slider 2, the second slider 21 and the cavity 6, a first inverted structure 71 is formed between the front side of one end of the bumper 7 and the cavity 6, and a second inverted structure 72 is formed between the right side surface of one end of the bumper 7 and the slider 2.

After the injection molding is completed, while the cavity 6 is opened upward, the ejector plate 42 rises and drives the inclined ejector rod 4 to move upward and backward, thereby driving the adjustable release buckle assembly to move upward and backward. While the slider 2 and the large inclined ejector rod 1 move backward synchronously, the slider 2 pulls the end of the bumper 7 backward through the cooperation of the second buckle structure, so that the first buckle structure of the bumper is separated from the cavity 6 from the front, as shown in Figure 3, completing the first stage of mold opening.

As shown in Figure 4, after the first stage of mold opening is completed, since the bumper and cavity 6 are completely unfastened, the cavity 6 can continue to open upward, and the outer surface of the bumper 7 (i.e., the front and upper surfaces in the figure) is in contact with the integrated cavity 6. No clamping line will be formed after demolding, ensuring the appearance. At the same time, the oil cylinder 3 and the second oil cylinder 31 on the large inclined top pull the slider 2 and the second slider 21 to both sides respectively, and the slider moves on the pressure strip 11 to exit the undercut stroke, so that the product is separated from the second buckle structure, and the mold is ejected, as shown in Figure 5.

During the first stage of mold opening, the slider moves synchronously with the large inclined top. Due to the matching relationship between the slider and the second undercut structure and the pulling direction (i.e., the undercut direction of the first undercut structure) is different from the undercut direction of the second undercut structure, the product can be deformed while moving to complete the undercut removal on the front side. After completing the first stage of mold opening, the slider moves on the large inclined top to exit the undercut stroke, realizes the undercut removal of the second undercut structure, and the product is demolded. By setting the slider, both the locking and driving of the product during the first stage of mold opening and the undercut removal during the second stage of mold opening are realized. Since the undercut removal of the cavity has been realized in the first stage of mold opening, the full opening of the cavity and the undercut removal of the slider can be realized at the same time in the second stage of mold opening, thereby improving efficiency.

Claims (7)

1. An adjustable slanted top and undercut mechanism for an injection mold, comprising a core (5) and a cavity (6), characterized in that it also comprises an adjustable undercut assembly, the adjustable undercut assembly being slidably arranged on the core (5), an injection cavity having a plurality of undercut structures being formed between the adjustable undercut assembly and the cavity (6), the undercut structures having different undercut directions, the adjustable undercut assembly moving in a mold opening direction while moving in one of the undercut directions; the undercut structures comprising a first undercut structure (71) and a second undercut structure (72) having different undercut directions, the adjustable undercut assembly comprising a large slanted top (1) and a slider (2), the large slanted top (1) being slidably arranged on the core (5), the large slanted top (1) moving in a mold opening direction while moving in the undercut direction of the first undercut structure (71), the slider (2) being slidably arranged on the large slanted top (1) along the undercut direction of the second undercut structure (72). 2. An adjustable inclined ejector and undercut mechanism for an injection mold according to claim 1, characterized in that a cylinder (3) is provided on the large inclined ejector (1), and an output end of the cylinder (3) is fixedly connected to a slider (2). 3. An adjustable slanted top release mechanism for an injection mold according to claim 1, characterized in that the large slanted top (1) is provided with a pressure strip (11) extending along the moving direction of the slider (2), and the slider (2) is slidably arranged between the pressure strip (11) and the large slanted top (1). 4. An adjustable tilting ejector and undercut mechanism for an injection mold according to claim 1, characterized in that it also includes a tilting ejector rod (4) and a universal slide (41), wherein the bottom end of the tilting ejector rod (4) is movably connected to the universal slide (41), and the top end of the tilting ejector rod (4) is connected to the bottom of the adjustable undercut assembly. 5. The adjustable tilting ejector and undercut mechanism for an injection mold according to claim 2, characterized in that a plurality of sliders (2) and oil cylinders (3) are provided respectively, and each slider (2) is slidably provided corresponding to the remaining undercut directions. 6. A method for removing undercuts from an injection mold using the injection mold adjustable tilting ejector undercut removal mechanism according to claim 2 or 5, characterized in that it comprises the following steps: a. The adjustable undercut assembly and the cavity (6) rise synchronously to perform the first stage of mold opening, and the adjustable undercut assembly moves in a direction away from the cavity (6) while rising. The adjustable undercut assembly cooperates with the undercut structure to pull one end of the product away from the cavity (6) to complete the first stage of undercutting; b. After the remaining undercut structures are removed, the cavity (6) is opened to carry out the second stage of mold opening. 7. A method for removing undercuts from an injection mold according to claim 6, characterized in that in step b, the slide block (2) is driven by the oil cylinder (3) to move on the large inclined top (1) along the removal direction of the remaining undercut structures.